Lady Gaga cancels 4 concerts; cites chronic pain

Pop star Lady Gaga has called off four shows this week because of chronic pain stemming from an undisclosed injury.

Scrapped are shows at Chicago's United Center tonight and Thursday, Detroit's Palace of Auburn Hills on Saturday and Copps Coliseum in Hamilton, Ontario, on Sunday.

There have been no other changes in the tour, which includes stops at the TD Garden in Boston on Feb.27 and the Mohegan Sun Casino in Uncasville, Conn., on March 3.

In a statement to fans on her Facebook page Tuesday night, Lady Gaga wrote: "I've been hiding a show injury and chronic pain for sometime now, over the past month it has worsened. I've been praying it would heal. I hid it from my staff, I didn't want to disappoint my amazing fans. However after last night's performance I could not walk and still can't."

She added, "To the fans in Chicago, Detroit & Hamilton I hope you can forgive me, as it is nearly impossible for me to forgive myself. I'm devastated & sad. It will hopefully heal as soon as possible, I hate this. I hate this so much. I love you and I'm sorry."

Lady Gaga's Born This Way Ball tour, which is in support of her 2011 album "Born this Way," began last April in South Korea. It is scheduled to conclude on March 20 in Tulsa, Oklahoma.